On what do with the estimated 11 million immigrants currently living in the country illegally? "We're going to have plenty of time to talk about it," he told reporters during a recent trip to the U.S. border with Mexico.

His plan to increase job growth? "You'll see details. But basically I'm telling you I'll just bring them back. It's called negotiation," he said.

As Trump pushes ahead with an establishment-bucking campaign for the Republican presidential nomination, the real estate developer and former reality TV star's decidedly unconventional approach to politics includes foregoing — so far — any substantive discussion of public policy.

It's one way, among many, that Trump stands out in the 2016 race.

Identifying problems and presenting preferred solutions is usually standard operating procedure for candidates for office at any level, perhaps none more so than president. Developing policy is a key role of campaign staff, and the resulting work is touted in speeches and rollouts designed to win headlines and voters alike.

Most of the other candidates for president in 2016 have records of public service, having cast votes as lawmakers or executed policy as governors. Those who lack such time in office, such as retired neurosurgeon Ben Carson, have still staked out clear positions on issues that include health care and managing the economy.

Trump's campaign website, meanwhile, provides a detailed account of his many real estate holdings and successful television show, but has no mention what he would seek to accomplish if elected president. During the first Republican primary debate of the 2016 season, Trump mostly avoided staking out any new positions on policy.

Republican 2016 U.S. presidential candidate businessman Donald Trump (L) talks with fellow candidate and former Governor of Florida Jeb Bush during a commercial break at the first official Republican presidential candidates debate of the 2016 U.S. presidential campaign in Cleveland, Ohio, August 6, 2015. REUTERS/Brian Snyder It's not an oversight, but rather part of Trump's political strategy.

"We're going to release some policy positions here in the near future," campaign manager Corey Lewandowski told The Associated Press. "Mr. Trump has looked at them and has decided that he's ready to release some of them."

But Lewandowski won't say when that might happen, other than "in the very near future." He declined to discuss the policy areas Trump would address, adding, "You'll have to wait and see."

Ex-Trump adviser Roger Stone, who quit the campaign over the weekend (Trump maintains he fired him) is said to have clashed with others on Trump's team over the lack of specifics offered by the campaign. Among other frustrations was the fact that a detailed job creation plan, along with issue papers on other major topics inspired by the candidate, had been left to sit on the shelf, unreleased, according to two people familiar with the campaign dynamics, who spoke independently to the AP on the condition of anonymity to avoid clashing with Trump.

That leaves only Trump's comments as a candidate and his many books as a preview of what's to come. They suggest his approach will largely be about setting broad-based goals, with little to no roadmap for reaching them, and he may lack consistency in both approach and ideology.

U.S. Republican presidential candidate Donald Trump speaks during a campaign event in Phoenix, Arizona Thomson Reuters On his early calling-card issue of immigration, for example, Trump has advocated for the building of an impenetrable wall across the length of the border with Mexico. He insists he will force the Mexican government to pay for its construction, but won't say how he'll accomplish such a feat of diplomacy.

"I've said that they're going to pay for the wall, and they will pay for the wall," he recently told Fox News when pressed for details.

After refusing to answer questions about what he would do with the millions of people already in the country illegally, Trump recently said during an interview he would deport them all, sort them into groups of "good ones" and "bad ones," and then allow those deemed good to re-enter the country via an "expedited" process.

He and his campaign staff, however, have not yet outlined details such as how a Trump administration would locate those individuals, the criteria for determining good and bad, and how much the plan would cost.

"The idea of large-scale deportations followed by selective re-admissions doesn't seem like a well-developed approach," said Marc Rosenblum, deputy director of the Immigration Policy Program at the non-partisan Migration Policy Institute. "Are you going to go knocking on doors and checking IDs? What is that going to look like?"

RICOH Women's British Open 2015 Thomson Reuters The lack of specificity, and Trump's shifting positions over time, also make it hard to predict what his approach might be to an issue of passionate importance to many Republican voters: the fate of the Affordable Care Act.

In his 2000 book, "The America We Deserve," Trump said the U.S. needed universal health care and pointed to Canada's single-payer system as a shining example. "I'm a conservative on most issues, but a liberal on this one," he wrote. A decade later, in 2011's "Time to Get Tough," Trump eviscerated what he now termed "socialized health care" as a jobs and business killer.

Asked in Thursday's debate about that shift, Trump argued that a single-payer systems "could have worked in a different age" in the U.S., but not now.

"What I'd like to see is a private system without the artificial lines around every state," he said. As for the people who can't take care of themselves? "I will do that through a different system," he said.

Trump has also evolved on other issues, as well.

Spencer Platt/Getty Images Fifteen years ago, he advocated for a one-time, 14.25 percent tax on individuals and trusts with a net worth over $10 million, which he estimated would raise $ 5.7 trillion in new revenue — enough, he said, to pay off "the entire national debt."

"That was a long time ago, but I was willing to do it, and it was a suggestion," Trump told ABC News' "This Week with George Stephanopoulos" Sunday.

Even on abortion, Trump has shifted over time. In an interview on "Meet The Press" in 1999, Trump said he was "very pro-choice." Yet he recently said he would shut down the federal government in order to cut off tax dollars for Planned Parenthood.

Challenged during the debate to explain such changes, Trump cited the example of former President Ronald Reagan — a hero in the Republican Party. "I'll tell you what. I've evolved on many issues over the years. And you know who else has? ... Ronald Reagan evolved on many issues," he said.

Republican presidential candidate Donald Trump speaks at FreedomFest, Saturday, July 11, 2015, in Las Vegas. AP Photo/John Locher Trump didn't always think that was one of Reagan's virtues. In his 1987 book, "The Art of the Deal," Trump suggested Reagan had conned the American people.

"He is so smooth and so effective a performer that he completely won over the American people," Trump wrote. "Only now, nearly seven years later, are people beginning to question whether there's anything beneath that smile."

None of this concerns Trump's most faithful supporters, who dismiss concerns about his lack of policy specifics or the changes in his ideology over time.

Michael Dunbar, who launched a "Draft Trump" campaign in 1987, said in an interview that he had no idea at that time what platform Trump would run on — or even what party he was registered with.

"It wasn't so much policy positions," he said. "I believe my sense was that he could just make it happen."